By the time he was 16, he had never written an essay. He didn’t know South Africa was a country. He couldn’t solve basic algebra problems.

“There were all these things that are part of this common collective of knowledge that 99 percent of people have that I didn’t have,” Powell said.

Powell was taught at home, his parents using a religious exemption that allows families to entirely opt out of public education, a Virginia law that is unlike any other in the country. That means that not only are their children excused from attending school — as those educated under the state’s home-school statute are — but they also are exempt from all government oversight.

School officials don’t ever ask them for transcripts, test scores or proof of education of any kind: Parents have total control.

Powell’s family encapsulates the debate over the long-standing law, with his parents earnestly trying to provide an education that reflects their beliefs and their eldest son objecting that without any structure or official guidance, children are getting shortchanged. Their disagreement, at its core, is about what they think is most essential that children learn — and whether government, or families, should define that.

While some national advocates fight for the right of parents to educate their children at home, Powell thinks children — most urgently, his siblings — should have the right to go to public school, too.